Validating turbulence/FI interaction reduced models through variation of effective FI scattering rate
2025 Research Campaign, Thrust: Fast Ions, Turbulence and Alfven Waves Interaction
Purpose of Experiment
This experiment seeks to measure how the amplitude of Alfven Eigenmodes, modes which expel the fast ions essential for achieving thermonuclear fusion plasma conditions, are changed when altering the effective scattering of these same fast ions. The study will attempt to measure how a single isolated Alfven Eigenmode’s amplitude changes as the plasma fast ion’s scattering conditions are modified. The experiment benefits from the extensive suite of DIII-D’s fast ion and turbulence diagnostics, which will be used to extensively document both the fast ion and turbulence plasma properties.
Experimental Approach
The experiment involves a series of controlled scans of the effective fast ion scattering rate, which depends on both the plasma microturbulence and rate of Coulomb collisions. The principal knob, increasing the plasma microturbulence, will be done by adding neutral beam power, injecting deuterium pellets, or seeding the plasma with extra carbon using the impurity powder dropper. These perturbations are expected to alter plasma turbulence from Ion Temperature Gradient (ITG) driven instabilities in the plasma.
See more details, including project leads, at U.S. Department of Energy, Office of Scientific and Technical Information (OSTI).